Re: [PATCH] perf data ctf: replace libbabeltrace with babeltrace2-ctf-writer
From: Michael Jeanson
Date: Wed May 20 2026 - 14:16:41 EST
On 2026-05-20 12:13, Ian Rogers wrote:
On Wed, May 13, 2026 at 9:06 AM Ian Rogers <irogers@xxxxxxxxxx> wrote:
On Wed, May 13, 2026 at 7:14 AM Michael Jeanson <mjeanson@xxxxxxxxxxxx> wrote:...
On 2026-05-12 17:54, Ian Rogers wrote:
This is cool, I'm surprised at how non-invasive the change is. I'd
done a similar thing but keeping both babeltrace 1 and 2. I'll post my
WIP in reply just as a heads up, but I have to do much more heavy
engineering.
I think I can rework this to try babeltrace2-ctf-writer first and fall
back on libbabeltrace1. The change is non-invasive because
bt2-ctf-writer is basically just a compat API for the ctf-writer of bt1
but it doesn't expose any of the new features of bt2.
Your WIP patch that uses the proper libbabeltrace2 API is definitely the
way to go for the long term. In the meantime would you like a v2 of this
patch?
We have a problem with the perf tool in that it carries too much
baggage due to its library dependencies, so I'd prefer we stick with
v2 support and your cleaner/simpler patch. I'm also hugely
appreciative of the work you've put in! I'm too busy to review my own
work right now, and cleaning this up ASAP offers an advantage.
* We support libbfd although libbfd is GPLv3 and license incompatible
with perf, which is mainly GPLv2. We carry around libunwind support
but that project appears unmaintained. We have LLVM support but the
LLVM dependency is huge in terms of size and dependencies it brings
in, so people avoid building with it, etc.
What's the plan here? I'd prefer to carry the v1 patch, ie let's lose
libbabeltrace (version 1) as a dependency.
I think I misunderstood you, I thought you wanted to keep the bt1 support as a fallback. I'm fine with either version of the patch being merged.
I can send an updated version of the v1 patch addressing your review comments.
Cheers,
Michael